Vaccination card availability and childhood immunization in Senegal.

BACKGROUND

The World Health Organization recommends recording vaccination status according to maternal recall in countries where administrative reporting systems are insufficiently reliable, as maternal recall in developing countries has been shown to be quite reliable compared with data from vaccination cards. This study aimed to investigate childhood vaccination coverage and its determinants according to the mothers' presentation of vaccination cards.

METHODS

The data come from the 2017 Senegalese Demographic and Health Survey, a nationally representative household survey of women aged 15-49 years, with a questionnaire focusing on children's health. This analysis was restricted to children aged 12-35 months (n = 4032) and it assessed vaccination coverage and associated sociodemographic factors with weighted multivariate logistic regressions. Stratified multivariate logistic regressions were also performed to investigate factors associated with routine childhood immunization uptake of the Bacillus Calmette-Guérin (BCG) vaccine, recommended for administration shortly after birth, as well as of the vaccines against yellow fever and measles (recommended at 9 months).

RESULTS

Comparison of vaccination coverage estimates according to the vaccination card or parental recall resulted in a 5-10% difference in estimated coverage for the BCG, pentavalent, measles, and yellow fever vaccines, but a huge difference for the polio vaccine (93.0% with the card, 32.0% without it). Presentation of the vaccination card was correlated with mothers' attendance at health facilities (suggesting it serves as a concrete manifestation of a bond between mothers and the healthcare system) and their region of residence, but it was not correlated with usually strong predictors of childhood vaccination, such as maternal education level. Factors associated with vaccinations differed depending on whether they were administered shortly after birth or later on.

CONCLUSIONS

Maternal recall was found to be quite reliable except for oral polio vaccination, which raises the possibility that complete immunization coverage rates could have been significantly underestimated due to potential confusion between injection and vaccination. Considering the ability to present vaccination cards as the materialization of a bond with the healthcare system, the decision path leading to vaccination among those who lack such a bond appears longer and more likely to be driven by supply-side effects.